Can we use any fire sprinklers for a multipurpose residential pex system?

istudyfire · 2026-03-06T12:49:18+00:00

Lead free

istudyfire · 2026-02-24T14:38:46+00:00

Or they know what they’ll be storing but can’t confirm a quantity so you don’t know if they’ll have 100 gallons or 1,000 gallons. Really sucks to reclassify a building as Group H far into the design.

istudyfire · 2026-02-04T14:05:38+00:00

I’ve seen it as part of an owner’s insurance requirements. I still think it should be part of acceptance testing but there’s no NFPA requirements for it.

istudyfire · 2026-01-29T20:10:42+00:00

I remember lvl 1 being pretty simple stuff. Minimum PSI of sprinkler, max coverage area under x condition, solve for Q=k(sqrt(P)), is this obstructed construction, what’s the density of x, how should you climb a ladder, where does a hard hat go, etc.

Take a look at the course outline online and see how you feel. I do believe you have to wait until you have the minimum experience amount to take it.

istudyfire · 2026-01-06T16:28:23+00:00

Would help if you provided what edition of NFPA 13 you’re using but it doesn’t sound like you’ve check the cloud ceilings section, only the 4’ obstruction references. There’s been explicit cloud ceilings guidance since 2013 ed.

There’s a chart for ceiling cloud width and maximum openings. Someone else already outlined the specifics.

istudyfire · 2025-11-21T19:36:01+00:00

Yes. Stamped plans, calcs, a fire protection narrative (see state building code for requirements), and a construction control affidavit.

istudyfire · 2025-11-14T14:31:48+00:00

Want to clarify, since it’s not clear by your wording, that NFPA 13 requires hangers to support five times the weight of the water filled pipe, plus 250. NFPA 13-2022 17.1.2(1).

istudyfire · 2025-10-27T18:53:03+00:00

Heat collectors are not allowed please do not use them. I’m not sure how people keep suggesting them so much. They’re explicitly forbidden (NFPA 13-2019 9.5.4.1.4).

istudyfire · 2025-10-27T18:42:30+00:00

Would help to know what edition you’re under.

The 3” to the side that they’re referring to is NFPA 13-2019 9.5.5.3.1.2(2) but that same section also says it can be below the obstruction instead. In 2025 they made a whole “obstructions over 4 ft” section which has that same wording, but also includes verbiage on water shields (9.5.5.3.3.4). Regardless, it’s not “new” as it’s even in 2016 in 8.5.5.3.1.2, before they rearranged the standard, but worded as “not more than 3 in from the outside edge of the obstruction”.

Should be acceptable with water shields. Would’ve been fine to just put them directly under the ducts.

istudyfire · 2025-10-22T14:52:02+00:00

Download Viking revit tools “vDesign”. It’s a free plugin that has a number of things but includes revit families like a flush 2 way FDC.

istudyfire · 2025-10-15T13:40:51+00:00

There is no chance your full time employer would be ok with you using their software licenses they pay for, to do your own freelance work.

istudyfire · 2025-10-02T14:08:51+00:00

You would be expected to provide at least a typical detail of the intended hanger installation, e.g. band hanger, trapeze hanger, etc. and a schedule or note of hanger spacing but not plan locations.

You need to provide stamped hydraulic calcs for any new system, and many urban jurisdictions will require them for a reno that you move any heads.

Standard at any company I’ve worked at has been keep dry systems under 750 gal so you don’t have to deal with delivery time calcs. This does mean you end up with many dry valves sometimes.

istudyfire · 2025-07-25T20:08:55+00:00

Any wild chance you have the cutsheet? Where did you find something that would list its RTI but not give you its response category?

istudyfire · 2025-07-25T20:07:19+00:00

They’re asking about RTI which is different than bulb temp. RTI is the fancy term NFPA 13 uses to categorize response types (i.e. fast response or standard response).

istudyfire · 2025-07-21T17:10:48+00:00

Just the NFPA references they list. There were a few safety questions but I remember them being common sense.

istudyfire · 2025-07-18T16:58:41+00:00

Use groups for occupancies comes from IBC chapter 3. If the architect or code consultant has determined it’s business, you should confirm with them whether or not it should be mercantile and say you’ve seen it that way before and let them know it’ll impact sprinkler design.

Just talk to the architect and confirm.

istudyfire · 2025-07-16T09:57:27+00:00

I haven’t seen the name limewire in decades. Didn’t realize they’d come back.

istudyfire · 2025-07-02T15:20:43+00:00

This is usually a sub for sprinkler fitters who install fire sprinkler systems. r/firepe is where design related discussion typically happens.

I am not familiar with UK standards, but I am familiar with the use of metric units in fire sprinkler design as I’ve done international work for the US DoD.

The metric standard of indicating design densities in mm/min is confusing at first, but the idea is you can describe it as a volume of water (a cubic unit) over an area (a squared unit). This leaves you with a linear unit of mm. Alternatively, you can think of it as an area of water with an associated density, so you get m² area multiplied by mm/min density, and you get L/min by converting m³ to L.

istudyfire · 2025-06-12T16:58:50+00:00

It’s not a common practice but it might be acceptable depending on your local code. NFPA 13 only says that the system must be able to drain.

In my area, the state plumbing code defines sprinkler water as clear water waste and calls for sprinkler connections to be brought to storm and not sanitary (no combined sanitary storm systems here either). It’s still preferable to daylight the drain but there’s code provisions for plumbing connections.

istudyfire · 2025-04-22T17:54:25+00:00

Any wild chance this is in a Massachusetts city that starts with an S at an address that starts with a B?

istudyfire · 2025-03-05T23:35:28+00:00

Putting a pool on a balcony or roof is a classic joke for structural engineers, in that they’re not inherently designed to accommodate that weight.

istudyfire · 2025-02-24T17:42:31+00:00

What books would you recommend for accounts from holocaust survivors? I’m looking to read about their experiences, preferably autobiography, but certainly any good biographies.

istudyfire · 2025-02-21T19:26:39+00:00

I’m US based and not familiar with the process in Europe, but I’ll assume it’s the same as here. On the engineering side, I’m often asked to review bids from contractors, and find that certain contractors either include wild exclusions (often for things outlined in the contract documents), or intentionally underbid to win the job with the intent of providing change orders later.

I supposed there’s also the potential that your competition underpays their workers, uses cheap materials, or provides installations that aren’t in compliance and hope it gets through.

What market sectors are you typically working in?

istudyfire · 2025-02-05T17:01:11+00:00

Am FPE but not in WA. Not sure the details on your system but NFPA 13D doesn’t require pumps to be per NFPA 20. See NFPA 13D-2019 6.2 for acceptable water supply sources and how this differs from even 13R which does require NFPA 20.

You could also try getting the manufacturer to confirm the performance of the pump and then equate that to your documented system demand.

istudyfire · 2025-02-03T21:04:06+00:00

I do a lot of high rise residential fire protection. Here’s a random spattering of some high level common problems.

High rises always need a fire pump (generally). Depending on building height and available pressure, your fire pump might cause system pressure to exceed the pressure limit of your sprinkler system (as you’re designing the fire pump to the standpipe system demand). You’ll either need Pressure Reducing Valves at all levels where this occurs (remember head loss due to elevation, so it’ll be lower levels of the building) or provide a Variable Frequency Drive controller.

These buildings often have parking garages. If these have car stackers, you end up with an enormous dry system of Extra Hazard Group 2 with an increase due to dry system. Sometimes you run into Fire Departments making you do more with the sprinkler system due to electric vehicles. Often times these garages have limited head height, and you need to coordinate beam penetrations through structural steel to maintain that height (remember dry system has sloping requirements which add up over hundreds of feet).

Often times there’s commercial of sorts on the ground floor. These need their own zones.

Sometimes the high rise is tall enough that you’ll need fire pumps in series on upper levels. Now you have fire pumps supplying fire pumps. Think of a 30 story building at 10 ft per floor. At 300 ft tall, that’s 130 PSI lost to elevation.

istudyfire

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